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Serologic response to rickettsial antigens in patients with Astrakhan fever
M E Eremeeva1, N M Balayeva, V F Ignatovich
1Unité des Rickettsies, CNRS EP J 0054, Faculté de Medicine, Marseille, France.
Abstract:
Astrakhan fever is a new spotted fever group (SFG) rickettsiosis. Sera of patients with Astrakhan fever have been examined by microimmunofluorescence and western immunoblotting to determine the serologic responses to the Astrakhan strain and to R. conorii M-1 strain and the Israelian isolate of SFG rickettsiae. The serologic response to specific rickettsial agent and to Israelian isolate has been found to be similar, but was different of that to R. conorii. Immunoglobulin G (IgG) and IgM antibodies were detected in most sera and were directed against the lipopolysaccharide. Only one of tested sera contained IgG antibodies which also recognized high molecular weight proteins.
Insights
Astrakhan fever, a spotted fever group rickettsiosis, elicits a distinct serologic response. Antibodies detected primarily target lipopolysaccharide, differentiating it from R. conorii infections.
Area of Science:
- Infectious Diseases
- Microbiology
- Immunology
Background:
- Astrakhan fever is an emerging rickettsiosis within the spotted fever group (SFG).
- Understanding the serological profile of Astrakhan fever is crucial for accurate diagnosis and differentiating it from other SFG rickettsioses.
Purpose of the Study:
- To characterize the serologic responses in patients with Astrakhan fever.
- To compare the immune response to the Astrakhan strain with other SFG rickettsiae, specifically R. conorii and an Israeli isolate.
Main Methods:
- Microimmunofluorescence and western immunoblotting techniques were employed.
- Patient sera were tested against the Astrakhan strain, R. conorii M-1, and an Israeli SFG rickettsiae isolate.
Main Results:
- Serologic responses to the Astrakhan strain and the Israeli isolate were similar but distinct from R. conorii.
- Immunoglobulin G (IgG) and IgM antibodies were prevalent, predominantly targeting lipopolysaccharide.
- A minority of sera showed IgG antibodies recognizing high molecular weight proteins.
Conclusions:
- Astrakhan fever demonstrates a unique serologic signature.
- The findings aid in distinguishing Astrakhan fever from other SFG rickettsioses based on antibody profiles.
